The Conservative leader has met with British officials in London.

Conservative Leader Andrew Scheer smiles for a photo with British Prime Minister Theresa May in a photo posted to Scheer's Facebook on March 8, 2018.

OTTAWA — Conservative Leader Andrew Scheer says nations that believe in free trade need to present a united front against the protectionist moves coming out of the United States.

Scheer was speaking from London, where he is travelling for a week of meetings with British officials and politicians including Prime Minister Theresa May, who he met with Thursday.

The trip comes during a big week in trade: International Trade Minister Francois-Philippe Champagne signed Canada onto the 11-member nation Trans-Pacific Partnership in Chile, then flies to Paraguay to launch free trade talks with the Mercosur trading bloc — the second-biggest in the Western Hemisphere after NAFTA, including South America's two biggest economies, Brazil and Argentina.

Countries that are committed to free trade need to help each other and work together to deal with these types of issues as they come out of the United States.Andrew Scheer

On the flip side Thursday, U.S. President Donald Trump announced new steel and aluminum tariffs of 25 per cent and 10 per cent, respectively — a subject Scheer said came up in many of his meetings this week. Although Canada is being exempted from the tariffs pending the outcome of NAFTA talks.

Countries like Canada and the U.K. that believe in free trade need to work together to convince the U.S. that protectionism is not the right path, Scheer said.

"Countries that are committed to free trade need to help each other and work together to deal with these types of issues as they come out of the United States," said Scheer.

The world managed to avoid the temptation of protectionism following the 2008 global recession, and those who believe in its benefits need to change the minds of those that don't, he added.

Scheer promoting post-Brexit trade deal

Scheer met with a number of different members of the British cabinet since his arrival, including foreign minister Boris Johnson and trade minister Liam Fox. However, the matter of tariffs did not come up during Scheer's conversation with May, where they stuck to the topic of free trade between Canada and the United Kingdom.

The premise of Scheer's entire trip is to promote his promise that establishing a free trade agreement with a post-Brexit Great Britain will be a top priority for him if he wins the next election in Canada in 2019.

May and Prime Minister Justin Trudeau laid the groundwork for a post-Brexit trade deal between Canada and the U.K. last fall when May visited Ottawa. They plan to use the Comprehensive Economic Trade Agreement, or CETA, as the template, tweaking it where needed. Britain is Canada's biggest trading partner in the EU currently.

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May set up a working group to explore the work necessary for a seamless transfer of CETA into a Canada-U.K. trade agreement after Britain leaves the EU, currently scheduled to happen a year from now.

Scheer says he isn't in England to criticize the current government's work on the file, but to stress how important it would be in a Conservative government in Canada.

Scheer also said his party is very concerned about the status of NAFTA negotiations and while he says any Canadian government would be challenged to deal with the Trump administration, the Liberals could have eased some anxieties by putting contingencies in the recent budget in the case NAFTA talks go badly.